config: docs for chains

src/config/Config.zig

@@ -1667,6 +1667,44 @@ class: ?[:0]const u8 = null,
 ///  - Notably, global shortcuts have not been implemented on wlroots-based
 ///    compositors like Sway (see [upstream issue](https://github.com/emersion/xdg-desktop-portal-wlr/issues/240)).
 ///
+/// ## Chained Actions
+///
+/// A keybind can have multiple actions by using the `chain` keyword for
+/// subsequent actions. When a keybind is activated, all chained actions are
+/// executed in order. The syntax is:
+///
+/// ```ini
+/// keybind = ctrl+a=new_window
+/// keybind = chain=goto_split:left
+/// ```
+///
+/// This binds `ctrl+a` to first open a new window, then move focus to the
+/// left split. Each `chain` entry appends an action to the most recently
+/// defined keybind. You can chain as many actions as you want:
+///
+/// ```ini
+/// keybind = ctrl+a=new_window
+/// keybind = chain=goto_split:left
+/// keybind = chain=toggle_fullscreen
+/// ```
+///
+/// Chained actions cannot have prefixes like `global:` or `unconsumed:`.
+/// The flags from the original keybind apply to the entire chain.
+///
+/// Chained actions work with key sequences as well. For example:
+///
+/// ```ini
+/// keybind = ctrl+a>n=new_window
+/// keybind = chain=goto_split:left
+/// ````
+///
+/// Chains with key sequences apply to the most recent binding in the
+/// sequence.
+///
+/// Chained keybinds are available since Ghostty 1.3.0.
+///
+/// ## Key Tables
+///
 /// You may also create a named set of keybindings known as a "key table."
 /// A key table must be explicitly activated for the bindings to become
 /// available. This can be used to implement features such as a